1. Technical Field
The disclosure relates to a touch display device, and more particular, to a touch display device having high touch resolution and high light utilization efficiency.
2. Description of the Prior Art
In varieties of modern consumer electronic products, portable electrical products such as flat computers, personal digital assistances (PDAs), mobile phones, global positioning systems (GPSs), audio players, etc. have widely utilized touch panels as human-machine interfaces in order to reduce volumes of the electronic products.
Based on different working mechanisms, touch display devices are mainly classified as: capacitive touch display devices, resistive touch display devices, and optical touch display devices. The optical touch display devices have been widely used because of high transparency. However, in the optical touch display devices, light emitting devices and photo-sensing devices are required to be disposed so as to provide touch-sensing functions. Therefore, the width and thickness of the frame regions of conventional optical touch display devices would be increased. Also, a large number of the light emitting devices are required in each conventional optical touch display device due to its poor light utilization efficiency. As a result, fabrication costs and power consumptions tend to increase, which retards the development of the optical touch display devices.